Switzerland is very selective with work permits for non-EU citizens. Your employer must prove no Swiss or EU citizen could fill the position. L permit is short-term (up to 1 year), B permit is longer-term (renewable). The salaries are among the highest in the world but cost of living is also very high.
Fees: CHF 88 visa fee + cantonal fees vary
Processing time: 2-4 months
Visa center in Algeria: Swiss Embassy Algiers
Find a Swiss employer willing to sponsor you. They must file a work permit request with the cantonal labor office, proving they couldn't find a qualified Swiss/EU candidate. Once approved, apply for a work visa at the Swiss Embassy in Algiers.
Estimated duration: 2-4 months