unsigned.c

#include <limits.h>
#include <stdio.h>

int main(void) {

    int value = -1;

    printf("UINT_MAX: %u\n", UINT_MAX);
    printf("value: %d\n", value);

    unsigned int uvalue = UINT_MAX - (unsigned int)value + 1U;

    printf("(unsigned int)value: %u\n", (unsigned int)value);
    printf("-(unsigned int)value: %u\n", -(unsigned int)value); // Does a 2's complement conversion

    printf("uvalue: %u\n", uvalue);

    return 0;
}

// Run with value = -1
// 
// UINT_MAX: 4294967295
// value: -1
// (unsigned int)value: 4294967295
// -(unsigned int)value: 1
// uvalue: 1

// Run with value = INT_MIN
// 
// UINT_MAX: 4294967295
// value: -2147483648
// (unsigned int)value: 2147483648
// -(unsigned int)value: 2147483648
// uvalue: 2147483648